Adding upstream version 1:2.43.0.upstream/1%2.43.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 866 insertions, 0 deletions

diff --git a/pathspec.c b/pathspec.c
new file mode 100644
index 0000000..bb1efe1
--- /dev/null
+++ b/pathspec.c
@@ -0,0 +1,866 @@
+#include "git-compat-util.h"
+#include "abspath.h"
+#include "parse.h"
+#include "dir.h"
+#include "environment.h"
+#include "gettext.h"
+#include "pathspec.h"
+#include "attr.h"
+#include "read-cache.h"
+#include "repository.h"
+#include "setup.h"
+#include "strvec.h"
+#include "symlinks.h"
+#include "quote.h"
+#include "wildmatch.h"
+
+/*
+ * Finds which of the given pathspecs match items in the index.
+ *
+ * For each pathspec, sets the corresponding entry in the seen[] array
+ * (which should be specs items long, i.e. the same size as pathspec)
+ * to the nature of the "closest" (i.e. most specific) match found for
+ * that pathspec in the index, if it was a closer type of match than
+ * the existing entry.  As an optimization, matching is skipped
+ * altogether if seen[] already only contains non-zero entries.
+ *
+ * If seen[] has not already been written to, it may make sense
+ * to use find_pathspecs_matching_against_index() instead.
+ */
+void add_pathspec_matches_against_index(const struct pathspec *pathspec,
+					struct index_state *istate,
+					char *seen,
+					enum ps_skip_worktree_action sw_action)
+{
+	int num_unmatched = 0, i;
+
+	/*
+	 * Since we are walking the index as if we were walking the directory,
+	 * we have to mark the matched pathspec as seen; otherwise we will
+	 * mistakenly think that the user gave a pathspec that did not match
+	 * anything.
+	 */
+	for (i = 0; i < pathspec->nr; i++)
+		if (!seen[i])
+			num_unmatched++;
+	if (!num_unmatched)
+		return;
+	for (i = 0; i < istate->cache_nr; i++) {
+		const struct cache_entry *ce = istate->cache[i];
+		if (sw_action == PS_IGNORE_SKIP_WORKTREE &&
+		    (ce_skip_worktree(ce) || !path_in_sparse_checkout(ce->name, istate)))
+			continue;
+		ce_path_match(istate, ce, pathspec, seen);
+	}
+}
+
+/*
+ * Finds which of the given pathspecs match items in the index.
+ *
+ * This is a one-shot wrapper around add_pathspec_matches_against_index()
+ * which allocates, populates, and returns a seen[] array indicating the
+ * nature of the "closest" (i.e. most specific) matches which each of the
+ * given pathspecs achieves against all items in the index.
+ */
+char *find_pathspecs_matching_against_index(const struct pathspec *pathspec,
+					    struct index_state *istate,
+					    enum ps_skip_worktree_action sw_action)
+{
+	char *seen = xcalloc(pathspec->nr, 1);
+	add_pathspec_matches_against_index(pathspec, istate, seen, sw_action);
+	return seen;
+}
+
+char *find_pathspecs_matching_skip_worktree(const struct pathspec *pathspec)
+{
+	struct index_state *istate = the_repository->index;
+	char *seen = xcalloc(pathspec->nr, 1);
+	int i;
+
+	for (i = 0; i < istate->cache_nr; i++) {
+		struct cache_entry *ce = istate->cache[i];
+		if (ce_skip_worktree(ce) || !path_in_sparse_checkout(ce->name, istate))
+		    ce_path_match(istate, ce, pathspec, seen);
+	}
+
+	return seen;
+}
+
+/*
+ * Magic pathspec
+ *
+ * Possible future magic semantics include stuff like:
+ *
+ *	{ PATHSPEC_RECURSIVE, '*', "recursive" },
+ *	{ PATHSPEC_REGEXP, '\0', "regexp" },
+ *
+ */
+
+static struct pathspec_magic {
+	unsigned bit;
+	char mnemonic; /* this cannot be ':'! */
+	const char *name;
+} pathspec_magic[] = {
+	{ PATHSPEC_FROMTOP,  '/', "top" },
+	{ PATHSPEC_LITERAL, '\0', "literal" },
+	{ PATHSPEC_GLOB,    '\0', "glob" },
+	{ PATHSPEC_ICASE,   '\0', "icase" },
+	{ PATHSPEC_EXCLUDE,  '!', "exclude" },
+	{ PATHSPEC_ATTR,    '\0', "attr" },
+};
+
+static void prefix_magic(struct strbuf *sb, int prefixlen, unsigned magic)
+{
+	int i;
+	strbuf_addstr(sb, ":(");
+	for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
+		if (magic & pathspec_magic[i].bit) {
+			if (sb->buf[sb->len - 1] != '(')
+				strbuf_addch(sb, ',');
+			strbuf_addstr(sb, pathspec_magic[i].name);
+		}
+	strbuf_addf(sb, ",prefix:%d)", prefixlen);
+}
+
+static size_t strcspn_escaped(const char *s, const char *stop)
+{
+	const char *i;
+
+	for (i = s; *i; i++) {
+		/* skip the escaped character */
+		if (i[0] == '\\' && i[1]) {
+			i++;
+			continue;
+		}
+
+		if (strchr(stop, *i))
+			break;
+	}
+	return i - s;
+}
+
+static inline int invalid_value_char(const char ch)
+{
+	if (isalnum(ch) || strchr(",-_", ch))
+		return 0;
+	return -1;
+}
+
+static char *attr_value_unescape(const char *value)
+{
+	const char *src;
+	char *dst, *ret;
+
+	ret = xmallocz(strlen(value));
+	for (src = value, dst = ret; *src; src++, dst++) {
+		if (*src == '\\') {
+			if (!src[1])
+				die(_("Escape character '\\' not allowed as "
+				      "last character in attr value"));
+			src++;
+		}
+		if (invalid_value_char(*src))
+			die("cannot use '%c' for value matching", *src);
+		*dst = *src;
+	}
+	*dst = '\0';
+	return ret;
+}
+
+static void parse_pathspec_attr_match(struct pathspec_item *item, const char *value)
+{
+	struct string_list_item *si;
+	struct string_list list = STRING_LIST_INIT_DUP;
+
+	if (item->attr_check || item->attr_match)
+		die(_("Only one 'attr:' specification is allowed."));
+
+	if (!value || !*value)
+		die(_("attr spec must not be empty"));
+
+	string_list_split(&list, value, ' ', -1);
+	string_list_remove_empty_items(&list, 0);
+
+	item->attr_check = attr_check_alloc();
+	CALLOC_ARRAY(item->attr_match, list.nr);
+
+	for_each_string_list_item(si, &list) {
+		size_t attr_len;
+		char *attr_name;
+		const struct git_attr *a;
+
+		int j = item->attr_match_nr++;
+		const char *attr = si->string;
+		struct attr_match *am = &item->attr_match[j];
+
+		switch (*attr) {
+		case '!':
+			am->match_mode = MATCH_UNSPECIFIED;
+			attr++;
+			attr_len = strlen(attr);
+			break;
+		case '-':
+			am->match_mode = MATCH_UNSET;
+			attr++;
+			attr_len = strlen(attr);
+			break;
+		default:
+			attr_len = strcspn(attr, "=");
+			if (attr[attr_len] != '=')
+				am->match_mode = MATCH_SET;
+			else {
+				const char *v = &attr[attr_len + 1];
+				am->match_mode = MATCH_VALUE;
+				am->value = attr_value_unescape(v);
+			}
+			break;
+		}
+
+		attr_name = xmemdupz(attr, attr_len);
+		a = git_attr(attr_name);
+		if (!a)
+			die(_("invalid attribute name %s"), attr_name);
+
+		attr_check_append(item->attr_check, a);
+
+		free(attr_name);
+	}
+
+	if (item->attr_check->nr != item->attr_match_nr)
+		BUG("should have same number of entries");
+
+	string_list_clear(&list, 0);
+}
+
+static inline int get_literal_global(void)
+{
+	static int literal = -1;
+
+	if (literal < 0)
+		literal = git_env_bool(GIT_LITERAL_PATHSPECS_ENVIRONMENT, 0);
+
+	return literal;
+}
+
+static inline int get_glob_global(void)
+{
+	static int glob = -1;
+
+	if (glob < 0)
+		glob = git_env_bool(GIT_GLOB_PATHSPECS_ENVIRONMENT, 0);
+
+	return glob;
+}
+
+static inline int get_noglob_global(void)
+{
+	static int noglob = -1;
+
+	if (noglob < 0)
+		noglob = git_env_bool(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, 0);
+
+	return noglob;
+}
+
+static inline int get_icase_global(void)
+{
+	static int icase = -1;
+
+	if (icase < 0)
+		icase = git_env_bool(GIT_ICASE_PATHSPECS_ENVIRONMENT, 0);
+
+	return icase;
+}
+
+static int get_global_magic(int element_magic)
+{
+	int global_magic = 0;
+
+	if (get_literal_global())
+		global_magic |= PATHSPEC_LITERAL;
+
+	/* --glob-pathspec is overridden by :(literal) */
+	if (get_glob_global() && !(element_magic & PATHSPEC_LITERAL))
+		global_magic |= PATHSPEC_GLOB;
+
+	if (get_glob_global() && get_noglob_global())
+		die(_("global 'glob' and 'noglob' pathspec settings are incompatible"));
+
+	if (get_icase_global())
+		global_magic |= PATHSPEC_ICASE;
+
+	if ((global_magic & PATHSPEC_LITERAL) &&
+	    (global_magic & ~PATHSPEC_LITERAL))
+		die(_("global 'literal' pathspec setting is incompatible "
+		      "with all other global pathspec settings"));
+
+	/* --noglob-pathspec adds :(literal) _unless_ :(glob) is specified */
+	if (get_noglob_global() && !(element_magic & PATHSPEC_GLOB))
+		global_magic |= PATHSPEC_LITERAL;
+
+	return global_magic;
+}
+
+/*
+ * Parse the pathspec element looking for long magic
+ *
+ * saves all magic in 'magic'
+ * if prefix magic is used, save the prefix length in 'prefix_len'
+ * returns the position in 'elem' after all magic has been parsed
+ */
+static const char *parse_long_magic(unsigned *magic, int *prefix_len,
+				    struct pathspec_item *item,
+				    const char *elem)
+{
+	const char *pos;
+	const char *nextat;
+
+	for (pos = elem + 2; *pos && *pos != ')'; pos = nextat) {
+		size_t len = strcspn_escaped(pos, ",)");
+		int i;
+
+		if (pos[len] == ',')
+			nextat = pos + len + 1; /* handle ',' */
+		else
+			nextat = pos + len; /* handle ')' and '\0' */
+
+		if (!len)
+			continue;
+
+		if (starts_with(pos, "prefix:")) {
+			char *endptr;
+			*prefix_len = strtol(pos + 7, &endptr, 10);
+			if (endptr - pos != len)
+				die(_("invalid parameter for pathspec magic 'prefix'"));
+			continue;
+		}
+
+		if (starts_with(pos, "attr:")) {
+			char *attr_body = xmemdupz(pos + 5, len - 5);
+			parse_pathspec_attr_match(item, attr_body);
+			*magic |= PATHSPEC_ATTR;
+			free(attr_body);
+			continue;
+		}
+
+		for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
+			if (strlen(pathspec_magic[i].name) == len &&
+			    !strncmp(pathspec_magic[i].name, pos, len)) {
+				*magic |= pathspec_magic[i].bit;
+				break;
+			}
+		}
+
+		if (ARRAY_SIZE(pathspec_magic) <= i)
+			die(_("Invalid pathspec magic '%.*s' in '%s'"),
+			    (int) len, pos, elem);
+	}
+
+	if (*pos != ')')
+		die(_("Missing ')' at the end of pathspec magic in '%s'"),
+		    elem);
+	pos++;
+
+	return pos;
+}
+
+/*
+ * Parse the pathspec element looking for short magic
+ *
+ * saves all magic in 'magic'
+ * returns the position in 'elem' after all magic has been parsed
+ */
+static const char *parse_short_magic(unsigned *magic, const char *elem)
+{
+	const char *pos;
+
+	for (pos = elem + 1; *pos && *pos != ':'; pos++) {
+		char ch = *pos;
+		int i;
+
+		/* Special case alias for '!' */
+		if (ch == '^') {
+			*magic |= PATHSPEC_EXCLUDE;
+			continue;
+		}
+
+		if (!is_pathspec_magic(ch))
+			break;
+
+		for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
+			if (pathspec_magic[i].mnemonic == ch) {
+				*magic |= pathspec_magic[i].bit;
+				break;
+			}
+		}
+
+		if (ARRAY_SIZE(pathspec_magic) <= i)
+			die(_("Unimplemented pathspec magic '%c' in '%s'"),
+			    ch, elem);
+	}
+
+	if (*pos == ':')
+		pos++;
+
+	return pos;
+}
+
+static const char *parse_element_magic(unsigned *magic, int *prefix_len,
+				       struct pathspec_item *item,
+				       const char *elem)
+{
+	if (elem[0] != ':' || get_literal_global())
+		return elem; /* nothing to do */
+	else if (elem[1] == '(')
+		/* longhand */
+		return parse_long_magic(magic, prefix_len, item, elem);
+	else
+		/* shorthand */
+		return parse_short_magic(magic, elem);
+}
+
+/*
+ * Perform the initialization of a pathspec_item based on a pathspec element.
+ */
+static void init_pathspec_item(struct pathspec_item *item, unsigned flags,
+			       const char *prefix, int prefixlen,
+			       const char *elt)
+{
+	unsigned magic = 0, element_magic = 0;
+	const char *copyfrom = elt;
+	char *match;
+	int pathspec_prefix = -1;
+
+	item->attr_check = NULL;
+	item->attr_match = NULL;
+	item->attr_match_nr = 0;
+
+	/* PATHSPEC_LITERAL_PATH ignores magic */
+	if (flags & PATHSPEC_LITERAL_PATH) {
+		magic = PATHSPEC_LITERAL;
+	} else {
+		copyfrom = parse_element_magic(&element_magic,
+					       &pathspec_prefix,
+					       item,
+					       elt);
+		magic |= element_magic;
+		magic |= get_global_magic(element_magic);
+	}
+
+	item->magic = magic;
+
+	if (pathspec_prefix >= 0 &&
+	    (prefixlen || (prefix && *prefix)))
+		BUG("'prefix' magic is supposed to be used at worktree's root");
+
+	if ((magic & PATHSPEC_LITERAL) && (magic & PATHSPEC_GLOB))
+		die(_("%s: 'literal' and 'glob' are incompatible"), elt);
+
+	/* Create match string which will be used for pathspec matching */
+	if (pathspec_prefix >= 0) {
+		match = xstrdup(copyfrom);
+		prefixlen = pathspec_prefix;
+	} else if (magic & PATHSPEC_FROMTOP) {
+		match = xstrdup(copyfrom);
+		prefixlen = 0;
+	} else {
+		match = prefix_path_gently(prefix, prefixlen,
+					   &prefixlen, copyfrom);
+		if (!match) {
+			const char *hint_path;
+
+			if (!have_git_dir())
+				die(_("'%s' is outside the directory tree"),
+				    copyfrom);
+			hint_path = get_git_work_tree();
+			if (!hint_path)
+				hint_path = get_git_dir();
+			die(_("%s: '%s' is outside repository at '%s'"), elt,
+			    copyfrom, absolute_path(hint_path));
+		}
+	}
+
+	item->match = match;
+	item->len = strlen(item->match);
+	item->prefix = prefixlen;
+
+	/*
+	 * Prefix the pathspec (keep all magic) and assign to
+	 * original. Useful for passing to another command.
+	 */
+	if ((flags & PATHSPEC_PREFIX_ORIGIN) &&
+	    !get_literal_global()) {
+		struct strbuf sb = STRBUF_INIT;
+
+		/* Preserve the actual prefix length of each pattern */
+		prefix_magic(&sb, prefixlen, element_magic);
+
+		strbuf_addstr(&sb, match);
+		item->original = strbuf_detach(&sb, NULL);
+	} else {
+		item->original = xstrdup(elt);
+	}
+
+	if (magic & PATHSPEC_LITERAL) {
+		item->nowildcard_len = item->len;
+	} else {
+		item->nowildcard_len = simple_length(item->match);
+		if (item->nowildcard_len < prefixlen)
+			item->nowildcard_len = prefixlen;
+	}
+
+	item->flags = 0;
+	if (magic & PATHSPEC_GLOB) {
+		/*
+		 * FIXME: should we enable ONESTAR in _GLOB for
+		 * pattern "* * / * . c"?
+		 */
+	} else {
+		if (item->nowildcard_len < item->len &&
+		    item->match[item->nowildcard_len] == '*' &&
+		    no_wildcard(item->match + item->nowildcard_len + 1))
+			item->flags |= PATHSPEC_ONESTAR;
+	}
+
+	/* sanity checks, pathspec matchers assume these are sane */
+	if (item->nowildcard_len > item->len ||
+	    item->prefix         > item->len) {
+		BUG("error initializing pathspec_item");
+	}
+}
+
+static int pathspec_item_cmp(const void *a_, const void *b_)
+{
+	struct pathspec_item *a, *b;
+
+	a = (struct pathspec_item *)a_;
+	b = (struct pathspec_item *)b_;
+	return strcmp(a->match, b->match);
+}
+
+void pathspec_magic_names(unsigned magic, struct strbuf *out)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
+		const struct pathspec_magic *m = pathspec_magic + i;
+		if (!(magic & m->bit))
+			continue;
+		if (out->len)
+			strbuf_addstr(out, ", ");
+
+		if (m->mnemonic)
+			strbuf_addf(out, _("'%s' (mnemonic: '%c')"),
+				    m->name, m->mnemonic);
+		else
+			strbuf_addf(out, "'%s'", m->name);
+	}
+}
+
+static void NORETURN unsupported_magic(const char *pattern,
+				       unsigned magic)
+{
+	struct strbuf sb = STRBUF_INIT;
+	pathspec_magic_names(magic, &sb);
+	/*
+	 * We may want to substitute "this command" with a command
+	 * name. E.g. when "git add -p" or "git add -i" dies when running
+	 * "checkout -p"
+	 */
+	die(_("%s: pathspec magic not supported by this command: %s"),
+	    pattern, sb.buf);
+}
+
+void parse_pathspec(struct pathspec *pathspec,
+		    unsigned magic_mask, unsigned flags,
+		    const char *prefix, const char **argv)
+{
+	struct pathspec_item *item;
+	const char *entry = argv ? *argv : NULL;
+	int i, n, prefixlen, nr_exclude = 0;
+
+	memset(pathspec, 0, sizeof(*pathspec));
+
+	if (flags & PATHSPEC_MAXDEPTH_VALID)
+		pathspec->magic |= PATHSPEC_MAXDEPTH;
+
+	/* No arguments, no prefix -> no pathspec */
+	if (!entry && !prefix)
+		return;
+
+	if ((flags & PATHSPEC_PREFER_CWD) &&
+	    (flags & PATHSPEC_PREFER_FULL))
+		BUG("PATHSPEC_PREFER_CWD and PATHSPEC_PREFER_FULL are incompatible");
+
+	/* No arguments with prefix -> prefix pathspec */
+	if (!entry) {
+		if (flags & PATHSPEC_PREFER_FULL)
+			return;
+
+		if (!(flags & PATHSPEC_PREFER_CWD))
+			BUG("PATHSPEC_PREFER_CWD requires arguments");
+
+		pathspec->items = CALLOC_ARRAY(item, 1);
+		item->match = xstrdup(prefix);
+		item->original = xstrdup(prefix);
+		item->nowildcard_len = item->len = strlen(prefix);
+		item->prefix = item->len;
+		pathspec->nr = 1;
+		return;
+	}
+
+	n = 0;
+	while (argv[n]) {
+		if (*argv[n] == '\0')
+			die("empty string is not a valid pathspec. "
+				  "please use . instead if you meant to match all paths");
+		n++;
+	}
+
+	pathspec->nr = n;
+	ALLOC_ARRAY(pathspec->items, n + 1);
+	item = pathspec->items;
+	prefixlen = prefix ? strlen(prefix) : 0;
+
+	for (i = 0; i < n; i++) {
+		entry = argv[i];
+
+		init_pathspec_item(item + i, flags, prefix, prefixlen, entry);
+
+		if (item[i].magic & PATHSPEC_EXCLUDE)
+			nr_exclude++;
+		if (item[i].magic & magic_mask)
+			unsupported_magic(entry, item[i].magic & magic_mask);
+
+		if ((flags & PATHSPEC_SYMLINK_LEADING_PATH) &&
+		    has_symlink_leading_path(item[i].match, item[i].len)) {
+			die(_("pathspec '%s' is beyond a symbolic link"), entry);
+		}
+
+		if (item[i].nowildcard_len < item[i].len)
+			pathspec->has_wildcard = 1;
+		pathspec->magic |= item[i].magic;
+	}
+
+	/*
+	 * If everything is an exclude pattern, add one positive pattern
+	 * that matches everything. We allocated an extra one for this.
+	 */
+	if (nr_exclude == n) {
+		int plen = (!(flags & PATHSPEC_PREFER_CWD)) ? 0 : prefixlen;
+		init_pathspec_item(item + n, 0, prefix, plen, ".");
+		pathspec->nr++;
+	}
+
+	if (pathspec->magic & PATHSPEC_MAXDEPTH) {
+		if (flags & PATHSPEC_KEEP_ORDER)
+			BUG("PATHSPEC_MAXDEPTH_VALID and PATHSPEC_KEEP_ORDER are incompatible");
+		QSORT(pathspec->items, pathspec->nr, pathspec_item_cmp);
+	}
+}
+
+void parse_pathspec_file(struct pathspec *pathspec, unsigned magic_mask,
+			 unsigned flags, const char *prefix,
+			 const char *file, int nul_term_line)
+{
+	struct strvec parsed_file = STRVEC_INIT;
+	strbuf_getline_fn getline_fn = nul_term_line ? strbuf_getline_nul :
+						       strbuf_getline;
+	struct strbuf buf = STRBUF_INIT;
+	struct strbuf unquoted = STRBUF_INIT;
+	FILE *in;
+
+	if (!strcmp(file, "-"))
+		in = stdin;
+	else
+		in = xfopen(file, "r");
+
+	while (getline_fn(&buf, in) != EOF) {
+		if (!nul_term_line && buf.buf[0] == '"') {
+			strbuf_reset(&unquoted);
+			if (unquote_c_style(&unquoted, buf.buf, NULL))
+				die(_("line is badly quoted: %s"), buf.buf);
+			strbuf_swap(&buf, &unquoted);
+		}
+		strvec_push(&parsed_file, buf.buf);
+		strbuf_reset(&buf);
+	}
+
+	strbuf_release(&unquoted);
+	strbuf_release(&buf);
+	if (in != stdin)
+		fclose(in);
+
+	parse_pathspec(pathspec, magic_mask, flags, prefix, parsed_file.v);
+	strvec_clear(&parsed_file);
+}
+
+void copy_pathspec(struct pathspec *dst, const struct pathspec *src)
+{
+	int i, j;
+
+	*dst = *src;
+	DUP_ARRAY(dst->items, src->items, dst->nr);
+
+	for (i = 0; i < dst->nr; i++) {
+		struct pathspec_item *d = &dst->items[i];
+		struct pathspec_item *s = &src->items[i];
+
+		d->match = xstrdup(s->match);
+		d->original = xstrdup(s->original);
+
+		DUP_ARRAY(d->attr_match, s->attr_match, d->attr_match_nr);
+		for (j = 0; j < d->attr_match_nr; j++) {
+			const char *value = s->attr_match[j].value;
+			d->attr_match[j].value = xstrdup_or_null(value);
+		}
+
+		d->attr_check = attr_check_dup(s->attr_check);
+	}
+}
+
+void clear_pathspec(struct pathspec *pathspec)
+{
+	int i, j;
+
+	for (i = 0; i < pathspec->nr; i++) {
+		free(pathspec->items[i].match);
+		free(pathspec->items[i].original);
+
+		for (j = 0; j < pathspec->items[i].attr_match_nr; j++)
+			free(pathspec->items[i].attr_match[j].value);
+		free(pathspec->items[i].attr_match);
+
+		if (pathspec->items[i].attr_check)
+			attr_check_free(pathspec->items[i].attr_check);
+	}
+
+	FREE_AND_NULL(pathspec->items);
+	pathspec->nr = 0;
+}
+
+int match_pathspec_attrs(struct index_state *istate,
+			 const char *name, int namelen,
+			 const struct pathspec_item *item)
+{
+	int i;
+	char *to_free = NULL;
+
+	if (name[namelen])
+		name = to_free = xmemdupz(name, namelen);
+
+	git_check_attr(istate, name, item->attr_check);
+
+	free(to_free);
+
+	for (i = 0; i < item->attr_match_nr; i++) {
+		const char *value;
+		int matched;
+		enum attr_match_mode match_mode;
+
+		value = item->attr_check->items[i].value;
+		match_mode = item->attr_match[i].match_mode;
+
+		if (ATTR_TRUE(value))
+			matched = (match_mode == MATCH_SET);
+		else if (ATTR_FALSE(value))
+			matched = (match_mode == MATCH_UNSET);
+		else if (ATTR_UNSET(value))
+			matched = (match_mode == MATCH_UNSPECIFIED);
+		else
+			matched = (match_mode == MATCH_VALUE &&
+				   !strcmp(item->attr_match[i].value, value));
+		if (!matched)
+			return 0;
+	}
+
+	return 1;
+}
+
+int pathspec_needs_expanded_index(struct index_state *istate,
+				  const struct pathspec *pathspec)
+{
+	unsigned int i, pos;
+	int res = 0;
+	char *skip_worktree_seen = NULL;
+
+	/*
+	 * If index is not sparse, no index expansion is needed.
+	 */
+	if (!istate->sparse_index)
+		return 0;
+
+	/*
+	 * When using a magic pathspec, assume for the sake of simplicity that
+	 * the index needs to be expanded to match all matchable files.
+	 */
+	if (pathspec->magic)
+		return 1;
+
+	for (i = 0; i < pathspec->nr; i++) {
+		struct pathspec_item item = pathspec->items[i];
+
+		/*
+		 * If the pathspec item has a wildcard, the index should be expanded
+		 * if the pathspec has the possibility of matching a subset of entries inside
+		 * of a sparse directory (but not the entire directory).
+		 *
+		 * If the pathspec item is a literal path, the index only needs to be expanded
+		 * if a) the pathspec isn't in the sparse checkout cone (to make sure we don't
+		 * expand for in-cone files) and b) it doesn't match any sparse directories
+		 * (since we can reset whole sparse directories without expanding them).
+		 */
+		if (item.nowildcard_len < item.len) {
+			/*
+			 * Special case: if the pattern is a path inside the cone
+			 * followed by only wildcards, the pattern cannot match
+			 * partial sparse directories, so we know we don't need to
+			 * expand the index.
+			 *
+			 * Examples:
+			 * - in-cone/foo***: doesn't need expanded index
+			 * - not-in-cone/bar*: may need expanded index
+			 * - **.c: may need expanded index
+			 */
+			if (strspn(item.original + item.nowildcard_len, "*") == item.len - item.nowildcard_len &&
+			    path_in_cone_mode_sparse_checkout(item.original, istate))
+				continue;
+
+			for (pos = 0; pos < istate->cache_nr; pos++) {
+				struct cache_entry *ce = istate->cache[pos];
+
+				if (!S_ISSPARSEDIR(ce->ce_mode))
+					continue;
+
+				/*
+				 * If the pre-wildcard length is longer than the sparse
+				 * directory name and the sparse directory is the first
+				 * component of the pathspec, need to expand the index.
+				 */
+				if (item.nowildcard_len > ce_namelen(ce) &&
+				    !strncmp(item.original, ce->name, ce_namelen(ce))) {
+					res = 1;
+					break;
+				}
+
+				/*
+				 * If the pre-wildcard length is shorter than the sparse
+				 * directory and the pathspec does not match the whole
+				 * directory, need to expand the index.
+				 */
+				if (!strncmp(item.original, ce->name, item.nowildcard_len) &&
+				    wildmatch(item.original, ce->name, 0)) {
+					res = 1;
+					break;
+				}
+			}
+		} else if (!path_in_cone_mode_sparse_checkout(item.original, istate) &&
+			   !matches_skip_worktree(pathspec, i, &skip_worktree_seen))
+			res = 1;
+
+		if (res > 0)
+			break;
+	}
+
+	free(skip_worktree_seen);
+	return res;
+}